SB2021020327 - Multiple vulnerabilities in SolarWinds Serv-U FTP Server
Published: February 3, 2021 Updated: April 17, 2023
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 vulnerabilities.
1) Incorrect default permissions (CVE-ID: CVE-2021-25276)
CWE-ID: CWE-276 - Incorrect Default Permissions
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to incorrect default permissions on the Windows "Users" directory. A local user with access to the system can view contents of files and obtain users' password hashes from the "%ProgramData%\RhinoSoft\Serv-U\Users\<DOMAIN>\" directory.
2) Cross-site scripting (CVE-ID: CVE-2020-35482)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
3) Code Injection (CVE-ID: CVE-2020-35481)
CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation. A remote attacker can send a specially crafted request and execute arbitrary macros on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
4) Path traversal (CVE-ID: CVE-2020-27994)
CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green
The vulnerability allows a remote user to perform directory traversal attacks.
The vulnerability exists due to input validation error when processing directory traversal sequences passed via the "dir" HTTP GET parameter. A remote user can send a specially crafted HTTP request and read arbitrary files on the system.
Example:
https:///[host]/?Command=List&dir=\..\*.*
5) Stored cross-site scripting (CVE-ID: CVE-2020-28001)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P/U:Clear
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Remediation
Install update from vendor's website.